An anti-corruption group lists Somalia, North Korea and Afghanistan as the most corrupt nations in the world.
Berlin-based Transparency International released its yearly index Tuesday based on the perceived levels of corruption compiled from interviews with people in 177 countries.
Its scale gives a corruption-free nation a score of 100, and in 2013 Somalia, North Korea and Afghanistan all scored eight points.
By contrast, the least corrupt nations are Denmark and New Zealand with 91 points, followed by Finland and Sweden with 89.
Robert Barrington, executive director of Transparency International, says the worst performing countries are usually those undergoing conflict.
"You find a closing down of the transparency in government and, in particular, you find a complete lack of accountability. The institutions of the state start to dissolve. And it's the citizens that suffer."
Sudan and South Sudan, which have lingering tensions from unresolved issues related to their 2011 split, also rank near the bottom along with Libya, which has dealt with militia violence since the uprising that ousted longtime dictator Moammar Gadhafi.
Barrington highlighted Rwanda as a nation that has seen improvement. In 2009, it ranked 89th in the world and rose to 49 in the 2013 rankings.
"Rwanda is a particularly interesting one because it did perform quite poorly for a number of years, but there's been a concerted government effort to tackle corruption, and that's now reaping rewards."
War-torn Syria has declined over the same period, dropping from the 126th spot in 2009 to 168th in 2013.